Rust would enjoy a breakout year in 2016, due to injuries in the Penguins organization. After recording 8 points in 33 games in the 2015–16 season, Rust signed a 2-year extension with Pittsburgh, along with fellow players Scott Wilson, and Tom Kühnhackl. On May 26, 2016, at the NHL Eastern Conference Finals, Rust became the 8th rookie in history to get multiple goals in a game 7. He scored the first goal of the 2016 Stanley Cup Finals.

On December 5, 2016, Rust first recorded his first career hat-trick in a 8–5 win over the Ottawa Senators.[4]

On April 20, 2017, Rust scored two pivotal goals in Game 5 of the Eastern Conference First Round meeting between the Penguins and the Blue Jackets. The Penguins ultimately won the game 5–2, and the series 4–1.

Rust is the younger brother of retired AHL player Matt Rust who also played for the Wilkes-Barre Scranton Penguins during the 2011–12 AHL season.[5] Rust, also known as Rusty, has a stutter when he speaks, but through his life he has learned to not let his stutter affect his confidence.[6] Rust graduated Notre Dame May 2014 with a degree in finance from the Mendoza College of Business.[7]